Jeff Rotman / Shipwrecked tanker on coral reef off Ras Muhammed, Red Sea, Egypt

Juergen Freund / The sunken wreck of HMAS Perth has formed an artifical reef off the coast of Albany, Western Australia

Juergen Freund / The sunken wreck of HMAS Perth has formed an artifical reef off the coast of Albany, Western Australia. Photographic display panel

Juergen Freund / Person diving the artifical reef which has developed on the sunken HMAS Perth. Albany, Western Australia

Michael Pitts / Looking down on the ventilators in the engine room of the shipwreck of the japanese WWII boat, 'Nippo Maru', Chuuk / Truk lagoon, Chuuk islands, Pacific ocean

Michael Pitts / Japanese Field Gun on the deck of the shipwrecked 'Nippo Maru', Truk / Chuuk Lagoon, Chuuk Islands, Pacific ocean

Michael Pitts / Bow gun on the wreck of the 'San Francisco Maru', Chuuk / Truk lagoon, Chuuk islands, Pacific ocean islands

Michael Pitts / Engine room ventilators on the shipwreck of the Japanese WWII boat, 'Seiko Maru', Chuuk / Truk lagoon, Chuuk islands, Pacific ocean

Roberto Rinaldi / Ka Hing wreck, Kudat Peninsula, Sabah, Borneo.

Roberto Rinaldi / Wreck, now an artificial reef, with sponges, oysters and sea fans. Kudat, Borneo.

Roberto Rinaldi / Honeycomb / Zigzag oyster (Hyotissa hyotis) on Ka-Hing wreck, north Sabah, Borneo, Malaysia.

Roberto Rinaldi / Bi tube sponges (Haplosclerida sp) in front of the crane on the Ka Hing wreck, Kudat Peninsula, Sabah, Borneo Model released.